Adjustable dumbbell



FIG. 1 is a perspective view of an adjustable dumbbell incorporating ournew design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a front end elevational view thereof;

FIG. 5 is a rear end elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The ornamental design for an adjustable dumbbell, as shown.